Initiatives such as the Trusted Computing Group's (TCG) Mobile Trusted Module (MTM) documents TCG Mobile Reference Architecture version 1.0 12 Jun. 2007 (Non Patent Citation 1) and TCG Mobile Trusted Module Specification version 1.0 12 Jun. 2007 (Non Patent Citation 2) describe how to start-up a device in an assured and trusted fashion. These methods have been thoroughly reviewed to ensure that trust and security is maintained throughout the boot process, so provide a useful baseline for those wanting to implement a device that can boot securely. A key component of this secure boot process is a RIM Certificate. This is a signed structure that defines what the current expected platform state should be, represented by a hash of a set of Platform Configuration Registers (PCRs), which themselves contain known, publically defined hash values. These PCRs act as integrity measurements that may be recorded in RIM Certificates to define an expected machine state. In addition, the RIM Certificate also specifies a PCR to be extended if the current state is verified. This extend process takes a specified PCR and calculates a new hash value based on the previous PCR value concatenated with a new known value defined within the RIM Certificate. A typical secure boot sequence as defined by the TCG starts with the initialization and self-verification of the core components such as the roots of trust for verification and for measurement (the RTV+RTM), the MTM itself and associated core MTM interface components. Next, additional components that support other parts of the firmware are started in a trusted fashion, for example, each of them is verified on their starting by another component having been booted before them. And finally the operating system runs to provide a secure and trusted path for client applications to access MTM services.    Patent Citation 1: US Patent Application No. 2005/0138414    Non Patent Citation 1: TCG Mobile Reference Architecture version 1.0 12 Jun. 2007    Non Patent Citation 2: TCG Mobile Trusted Module Specification version 1.0 12 Jun. 2007